The present application relates to semiconductor device fabrication, and more particularly to a method of forming fin-type field effect transistors (FinFETs) including compound semiconductor fins.
As silicon-based semiconductor devices scale down to atomic-scale limits, they are running out of ways to increase performance and lower power consumption. By integrating higher performance materials with silicon, such as III-V compound semiconductor materials that provide higher carrier velocity and higher drive current, the hybrid semiconductor devices enable continued scaling beyond the capabilities of silicon alone.
Growing III-V compound semiconductor materials on sidewalls of silicon mandrel structures has been shown as a promising approach to grow defect-free III-V compound semiconductor fins on silicon. Following formation of the sidewall fins, the mandrel structures are selectively removed, leaving only the sidewall fins. However, when the feature sizes in integrated circuits continue to decrease, removal of the mandrel structures can cause sidewall fins to collapse. To prevent the collapse of the sidewall fins, the sidewalls fins need to be anchored at the ends. The presence of the anchoring structures leads to a decrease in device density in integrated circuits. Therefore, a method of forming free-standing III-V compound semiconductor sidewall fins without the need of anchoring structures remains needed.